Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drive Engines (Replaces 807166A1)

Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drive Engines (Replaces 807166A1)

This water shutter kit is engineered for MerCruiser stern drive engines equipped with 4" exhaust systems, covering a wide range of V6 and V8 models from 1996 to the present. The water shutters function as essential check valves, preventing water from flowing back into the engine's exhaust system when it is shut off or idling at low RPMs. This protects internal components from water damage and corrosion.

This kit is a direct aftermarket replacement for MerCruiser part 807166A1 and other equivalent part numbers. It includes all necessary components for a complete renewal of the exhaust bellows and water shutters, ensuring a proper seal and reliable performance.

• Installation Location: Mounts inside the exhaust Y-Pipe.
• Engine Compatibility: Fits gasoline MerCruiser V6 & V8 engines with 4" exhaust systems.
• Complete Kit: Includes water shutters, upper/lower bellows, and stainless steel clamps.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

MerCruiser Sterndrive Models

MerCruiser Inboard Models

Technical Specifications

Package Contents

• 2 x Water Shutters/Flappers (Replaces 807166A1)
• 2 x Lower Exhaust Bellows (Replaces 32-14358T / 32-14358001)
• 2 x Upper Exhaust Bellows (Replaces 32-44348T / 32-44348001)
• 4 x Stainless Steel Clamps

Installation Guide

1. Safety First: Disconnect the boat's battery before beginning any work.
2. Access Components: Gain access to the stern drive's exhaust Y-pipe where the bellows and shutters are located. This may require removing the drive unit.
3. Remove Old Parts: Carefully cut and remove the old upper and lower exhaust bellows and their clamps.
4. Extract Water Shutters: Reach into the Y-pipe and remove the old, worn water shutters. Note their orientation.
5. Clean Surfaces: Thoroughly clean the mounting surfaces on the Y-pipe and bell housing, removing any old adhesive or rubber residue.
6. Install New Shutters: Insert the new water shutters into the Y-pipe, ensuring they are oriented correctly to prevent water backflow.
7. Install Bellows: Slide the new upper and lower bellows into place, ensuring a snug fit on both ends.
8. Secure Clamps: Position the stainless steel clamps over the bellows and tighten them securely. Do not overtighten.
9. Final Check: Re-install the drive unit if it was removed. Reconnect the battery. Once in the water, start the engine and check for any exhaust or water leaks around the new components.

Troubleshooting & FAQ

Q: How do I know if this kit fits my MerCruiser engine?

A: This kit is specifically designed for MerCruiser V6 and V8 stern drive engines from 1996 to present that use a 4" diameter exhaust system. It is critical to confirm your exhaust size. This kit will not fit V6 engines with a one-piece exhaust manifold, as those typically require part number 807166A2. Always check the compatible models list and your engine's specifications.

Q: What are the common signs of a failing water shutter?

A: The most common failure signs include a distinct rattling or "clapping" noise from the exhaust area at idle, water entering the engine cylinders (which can lead to hydrolock), or visible cracks, stiffness, or missing pieces on the old shutters during an inspection.

Q: What is the purpose of the 2-piece "clapper" design?

A: The 2-piece "clapper" design functions as a passive one-way check valve. The flappers are pushed open by exhaust pressure when the engine is running, allowing exhaust to exit freely. When the engine is off or at very low RPMs, they close to create a seal that prevents water from surging back up the exhaust pipe and into the engine.

Q: OEM vs. Aftermarket?

A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?

A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?

A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.